Lock mechanism for rotary component control

ABSTRACT

A lock mechanism for controlling a rotating component including an outer shaft attachable to a stationary component and having a slotted ring defining capture slots and an interior annular space, a control ring having a first end disposed in the annular space, an inner shaft attachable to a rotating component configured to rotate relative to the stationary component, and the inner shaft engaged with a second end of the control ring, a first collar rotatably disposed around the slotted ring, the first collar having a plurality of release recesses, and a plurality of first bearings respectively retained within the capture slots beneath the first collar. In a first rotational position of the first collar, the plurality of release recesses align with the capture slots to rotationally disengage the rotating and stationary components. In a second rotational position of the first collar, the plurality of release recesses misalign with the capture slots to rotationally engage the rotating and stationary components.

BACKGROUND

Vehicle seats such as aircraft passenger seats are commonly equippedwith rotating components. For example, seats may be equipped with one ormore of backrests that pivot between upright and reclined positions, legrests that pivot between stowed and deployed positions, armrests thatpivot between stowed and deployed positions, etc. A backrest, forexample, is usually pivotally-mounted between seat-assembly framemembers fixed to the floor of an aircraft, and the recline angle of abackrest can typically be controlled for the comfort, convenience, andsafety of an occupant passenger. A leg rest, for example, is usuallypivotally-mounted to a forward end of a seat bottom and is typicallyangularly adjustable for the comfort of an occupant passenger. Anarmrest, for example, is usually pivotally-mounted to a stationary framemember and is typically adjustable between stowed and deployed positionsfor comfort and for seat ingress and egress of an occupant passenger.

Conventional mechanisms for the rotary control of such componentsinclude push button actuators coupled to remote locking devices such asgas springs, wherein actuating the actuator releases the remote lockingdevice allowing the component to be repositioned. Such conventionalmechanisms are disadvantageous in that they require separate mountinglocations for the actuator and the remote locking device, are prone tofailure, and are not able to incorporate secondary functions.

Accordingly, what is needed is a new control mechanism for rotatingcomponents that overcomes the disadvantages of conventional mechanisms.

SUMMARY OF THE INVENTIVE ASPECTS

To achieve the foregoing and other advantages, the inventive aspectsdisclosed herein are directed to a lock mechanism for rotary controlincluding an outer shaft attachable to a stationary component, the outershaft having a slotted ring defining capture slots and an interiorannular space, a control ring having a first end disposed in the annularspace, an inner shaft attachable to a rotating component, the rotatingcomponent configured to rotate relative to the stationary component, andthe inner shaft engaged with a second end of the control ring, a firstcollar rotatably disposed around the slotted ring, the first collarhaving a plurality of release recesses, and a plurality of firstbearings respectively retained within the capture slots beneath thefirst collar. In a first rotational position of the first collar, theplurality of release recesses align with the capture slots torotationally disengage the rotating and stationary components, In asecond rotational position of the first collar, the plurality of releaserecesses misalign with the capture slots to rotationally engage therotating and stationary components.

In some embodiments, the stationary component may be stationary seatassembly component and the rotating component may be a pivoting seatassembly component.

In some embodiments, in the first rotational position of the firstcollar, the first bearings may be partially offset from the captureslots toward the control ring; and, in the second rotational position ofthe first collar, the first bearings can partially offset from thecapture slots toward the first collar.

In some embodiments, the outer shaft may include a central shaft, andthe interior annular space may be defined between the central shaft andthe slotted ring.

In some embodiments, the central shaft may have a longitudinal end thatextends beyond the slotted ring and is received by the inner shaft.

In some embodiments, the lock mechanism may include a second collarrotatably disposed around an end of the inner shaft, wherein in a firstrotational position of the second collar the inner shaft isnon-rotationally engaged with the second end of the control ring, and ina second rotational position of the second collar the inner shaft isrotationally disengaged from the second end of the control ring.

In some embodiments, the lock mechanism may further include a pluralityof second bearings respectively retained within capture holes in the endof the inner shaft beneath the second collar, wherein, in the firstrotational position of the second collar, the second bearings arepartially offset from the capture holes toward the control ring; and, inthe second rotational position of the second collar, the second bearingscan partially offset from the capture holes toward the second collar.

In some embodiments, the lock mechanism may further include a manualcontrol device engaging the first collar and operable to move the firstcollar between a first rotational position and a second rotationalposition thereof.

In some embodiments, the lock mechanism may further include an automaticrelease device engaging the second collar and operable to move thesecond collar between a first rotational position and a secondrotational position thereof.

In some embodiments, the automatic release device may include aninertial mass on a trigger arm movable by inertial forces to move thesecond collar to the second rotational position.

In some embodiments, the lock mechanism may further include an armpivotally-mounted on the inner shaft.

In some embodiments, the control ring may have helical grooves in whichthe first bearings are movable against the forces of springs, when thefirst collar is in the first rotational position, by a force to overcomethe springs thereby permitting the rotating component to rotate relativeto the stationary component.

The inventive aspects disclosed herein are further directed to apassenger seat assembly including a stationary frame member, a rotatingcomponent configured to rotate relative to the stationary frame member,and a lock mechanism for controlling rotation of the rotating componentrelative to the stationary frame member. The lock mechanism includes anouter shaft attached to the stationary frame member, the outer shafthaving a slotted ring defining capture slots and an interior annularspace, a control ring having a first end disposed in the annular space,an inner shaft attached to the rotating component, the inner shaftengaged with a second end of the control ring, a first collar rotatablydisposed around the slotted ring, the first collar having a plurality ofrelease recesses, and a plurality of first bearings respectivelyretained within the capture slots beneath the first collar. In a firstrotational position of the first collar the plurality of releaserecesses align with the capture slots to rotationally disengage thestationary frame member and rotating component. In a second rotationalposition of the first collar, the plurality of release recesses misalignwith the capture slots to rotationally engage the stationary framemember and the rotating component.

In some embodiments, the rotating component may be a backrest, a legrest, or an armrest.

In some embodiments, in the first rotational position of the firstcollar the first bearings are partially offset from the capture slotstoward the control ring; and, in the second rotational position of thefirst collar the first bearings can partially offset from the captureslots toward the first collar.

In some embodiments, the lock mechanism further includes a manualcontrol device engaging the first collar and operable to move the firstcollar between first rotational position and second rotational positionthereof.

Embodiments of the inventive concepts may include one or more or anycombination of the above aspects, features and configurations.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the inventive concepts disclosed herein may be betterunderstood when consideration is given to the following detaileddescription thereof. Such description makes reference to the includeddrawings, which are not necessarily to scale, and in which some featuresmay be exaggerated, and some features may be omitted or may berepresented schematically in the interest of clarity. Like referencenumbers in the drawings may represent and refer to the same or similarelement, feature, or function. In the drawings:

FIG. 1 is a front elevation view of a passenger seat assembly includinga multi-functional rotary lock mechanism according to the presentdisclosure;

FIG. 2 is a perspective view of a rotary lock mechanism according to thepresent disclosure;

FIG. 3 is another perspective view of the rotary lock mechanism of FIG.2;

FIG. 4 is an exploded perspective view of the rotary lock mechanism ofFIG. 3;

FIG. 5 is a perspective view of the inner shaft and outer shaft of therotary lock mechanism shown in partial assembly of the rotary lockmechanism;

FIG. 6 is a perspective view of the control ring of the rotary lockmechanism showing several separately purposed bearings for illustrationof their respective functions;

FIG. 7 is an enlarged perspective view of the manual recline collar ofthe rotary lock mechanism;

FIG. 8 is a side view of several components of the rotary lock mechanismshown for illustration of manual recline features;

FIG. 9 is an enlarged perspective view of the automatic release collarof the rotary lock mechanism;

FIG. 10 is an enlarged side view of the inner shaft of the rotary lockmechanism;

FIG. 11 is a side view of several components of the rotary lockmechanism shown for illustration of locked positions of the automaticrelease collar and an automatic release device;

FIG. 12 is a side view of the components of FIG. 11 shown forillustration of release positions of the automatic release collar andautomatic release device;

FIG. 13 is a perspective view of several components of the rotary lockmechanism shown for illustration of a first position of a table supportarm; and

FIG. 14 is a perspective view of several components of the rotary lockmechanism shown for illustration of a second position of the tablesupport arm.

DETAILED DESCRIPTION

The inventive concepts are described hereinafter with reference to theaccompanying drawings in which exemplary embodiments are shown. However,the inventive concepts may be embodied in many different forms andshould not be construed as limited to the representative embodiments setforth herein.

A multi-functional rotary lock mechanism according to the presentdisclosure can be used, for example, as a seat recline mechanism for anaircraft passenger seat assembly as shown in FIG. 1. Other uses include,but are not limited to, leg rest rotary control, armrest rotary control,and rotary control of other components that are a part of or areseparate from a seat. For illustrative purposes, the rotary lockmechanism is shown mounted between a first seat assembly component,referenced as a stationary frame member 32, and a second seat assemblycomponent, referenced as a pivoting backrest 34. The backrest 34 of theseat assembly is pivotable about a horizontal pivot axis under controlof the rotary lock mechanism by several modes. While the rotary lockmechanism is described and shown herein with reference to a pivotingbackrest, it is understood that the rotary lock mechanism may beutilized to control motion between a stationary component (e.g., framemember) and a rotating component (e.g., leg rest, armrest), or betweentwo rotating components.

Under manual control, for example by a passenger, the rotary lockmechanism permits the backrest 34 to be manually reclined. Upon use of amanually actuated recline control device, a user can adjust the reclineangle of the backrest 34 to an upright position, a partial reclinedposition, and a maximum reclined position. A manual override featurepermits the recline setting to be overcome by force imparted on thebackrest 34, for example by a passing attendant, to return the backrest34 to the upright position, for example for taxi-take-off, and landingoperations. The manual override feature also serves as an optionalbreakover feature in the event of an aft-seated passenger impacting abackrest. By permitting a reclined backrest to return to upright underforce, injury to an aft-seated passenger may be avoided or at leastreduced by energy dissipation as the backrest returns toward upright.

A further breakover feature facilitates an automatic inertial release topermit the backrest to pivot forward under such emergency circumstancessuch as rapid aircraft decelerations and impacts. The further breakoverfeature is intended to normally prevent the backrest 34 from pivotingforward past an upright position toward the seat pan, while allowingthis movement if sufficient inertial forces due to deceleration orimpact occur. The automatic inertial release feature is activated byinertial forces upon the passenger seat assembly, which may precede anaft-seated passenger imparting forces upon a backrest. Thus, by thisfeature, the backrest may be released to pivot forward as or before apassenger strikes the backrest from behind.

Optionally, the rotary mechanism may also supports a tray table or otherstructure by way of rotatably engaging a component such as a tablesupport arm. Thus, multiple functions for use in a passenger seatassembly are facilitated by the multi-functional rotary lock mechanismwhen mounted between the pivoting backrest 34 and stationary framemember 32 of an aircraft passenger seat assembly as shown in FIG. 1.

Referring to FIGS. 2-3, a non-limiting example of a multi-functionalrotary lock mechanism is shown generally at reference numeral 20. Asshown in the exploded perspective view of FIG. 4, some components of thecomponents of the rotary lock mechanism are aligned along a pivot axis22, which defines a rotational axis around which relative movementoccurs in a pivoting joint facilitated by the rotary lock mechanism 20.While each component of the friction mechanism 20 could be described ashaving a separate axis, the pivot axis 22 is referenced in several ofthe other drawings for convenience, with the understanding that therespective axes of the components of the friction mechanism are alignedupon assembly. Thus, the pivot axis 22 serves as a reference line inthese descriptions. The pivot axis 22 is shown as a cross in views takenalong the axis.

Terms such as radially outward refer to features directed away from thepivot axis 22. Terms such as circumferential refer to features spaced orextended around the pivot axis. Terms such as longitudinal refer tofeatures extending along or parallel to the pivot axis 22. Somecomponents that are aligned along the pivot axis in the assembledmechanism are shown in FIG. 4 as offset for illustrative purpose to showtheir approximate longitudinal positions relative to other parts withwhich they are associated or on which they are mounted.

A first shaft at a first longitudinal end 24 of the rotary lockmechanism 20 is referenced as an outer shaft 26. A second shaft at asecond longitudinal end 28 of the rotary lock mechanism 20 is referencedas an inner shaft 30. In use, the rotary lock mechanism 20 is to beconnected at the opposite longitudinal ends to respective structuresbetween which relative pivotal motion is to be controllably permitted.In the example of FIG. 1, the outer shaft 26 is connected to thestationary frame member 32 and the inner shaft 30 is connected to thepivoting backrest 34. The outer shaft 26 includes a longitudinallyextending cylindrical central shaft 36 concentrically surrounded by aslotted ring 38, both of which are connected to a base plate 40 that isgenerally planar and perpendicular to the pivot axis 22. The base plate40 has mounting holes 42 by which the outer shaft 26 can benon-rotationally attached to a fixed structure, such as the frame member32 of FIG. 1, using fasteners, such as the bolts 44 as illustrated. Aninterior annular space 35 is defined between the central shaft 36 aslotted ring 38. The slotted ring concentrically surrounds the centralshaft 36 from the base plate 40 to the longitudinal end 46 of theslotted ring 38 opposite the base plate 40. The central shaft 36 extendslongitudinally beyond the slotted ring 38 to engage certain othercomponents of the rotary lock mechanism 20. A circumferential lockinggroove 48 defined near the longitudinal end 50 of the central shaft 36receives a lock ring 52 in the assembled mechanism to retain certaincomponents on the central shaft 36.

In keeping with the example of FIG. 1, in which the outer shaft 26 isconnected to the stationary frame member 32, the outer shaft serves as afixed frame of reference in these descriptions, whereas the inner shaft30 is controllably permitted to partially rotate relative to the outershaft 26. A first longitudinal end 54 of a control ring 56 is receivedin the annular space 35 of the outer shaft between the central shaft 36and slotted ring 38. The control ring 56 abuts the base plate 40 withinthe annular space 35. First-end tabs 58 (FIGS. 3-5) that extend from thefirst end of the control ring 56 are received by respectivecircumferentially arcuate slots 60 (FIGS. 3,5) in the base plate 40. Thearcuate lengths of the slots 60 relative to smaller circumferentialdimensions of the first-end tabs 58 permit the control ring 56 to pivotrelative to the outer shaft 26 within a limited recline rangecorresponding to the range of recline available to the backrest 34 inthe example of FIG. 1.

As briefly described above, the rotary lock mechanism 20 has bothmanually controlled recline and override features, by which the reclineposition of a backrest 34 can be adjusted, and an automatic releasefeature, which permits the backrest to pivot forward under suchemergency circumstances. The manual recline and override features aredescribed before the automatic release feature in the following.

Under manual control, the control ring 56 is non-rotationally engagedwith the inner shaft 30, and partial rotations of the control ring 56relative to the outer shaft 26 correspond to adjustment of the reclineangle of the backrest 34. Rotation of the inner shaft 30 relative to theouter shaft 26 is selectively controlled by use of a first collar,referenced as the manual recline collar 62. Partial rotations of themanual recline collar 62 (FIG. 4) lock and unlock the control ring 56for partial rotation relative to the outer shaft 26 within the reclinerange.

As shown in FIG. 5, linear and longitudinally extending recline-bearingcapture slots 64 are uniformly spaced circumferentially around thecontrol ring 56. Each capture slot 64 is closed at its first enddirected toward the base plate 40 and at its second end directed towardthe longitudinal end 46 of the slotted ring 38. Each capture slot 64 isdefined through the slotted ring 38, permitting a respective firstbearing, referenced as a recline bearing 70, within each slot 64 topartially offset radially inward from the slot toward the control ring56 or partially offset radially outward from the slot toward the manualrecline collar 62. The recline bearings 70 are dimensioned to remainpartially within the capture slots in either partially offset position.The recline bearings 70 are shown as ball bearings in the illustratedexample.

Each recline bearing 70 is captured radially beneath the manual reclinecollar 62 within a respective capture slot 64 with a respective linearbias spring 72 that persistently presses the recline bearing 70 towardthe second end of the slot. With the recline bearings 70 maintained atthe second end of the capture slots 64, the rotational position of themanual recline collar 62 determines whether the control ring 56 canrotate relative to the slotted ring 38 according to whether the reclinebearings 70 are pressed inward to engage the control ring 56 orpermitted to offset outward to disengage the control ring 56. Thesefeatures relate to manual recline control, with reference to thepivoting backrest 34 of FIG. 1.

FIG. 6 shows several recline bearings 70 engaged with the control ring56 without the outer ring for illustration purposes. The control ring 56has recline control grooves 76 in one-to-one correspondence with therecline bearings 70 and the capture slots 64 of the slotted ring 38. Therecline control grooves 76 are uniformly spaced circumferentially aroundthe exterior of the control ring 56. Each recline control groove 76 hasmultiple index positions for receiving the respective recline bearing 70and corresponding to indexed pivotal positions of the control ring 56relative to the outer shaft 26. In the illustrated example, each reclinecontrol groove 76 has a first index position 81, a second index position82, and a third index position 83, corresponding respectively toincreasingly rotated positions of the control ring 56 relative to theouter shaft 26. In the example of FIG. 1, the index positions 81-83correspond respectively to the upright position, the partial reclinedposition, and the maximum reclined position, of the backrest 34 relativeto the frame member 32 of the seat assembly.

In the assembled rotary lock mechanism 20, (FIG. 3), the manual reclinecollar 62 abuts the base plate 40 of the outer shaft 26 and surroundsthe slotted ring 38. As shown in FIG. 7, the manual recline collar 62has a first end for abutting the base plate 40. The first end of themanual recline collar 62 has pivot limit gaps 86, each of which receivesa respective stop tab 88 that extends from the base plate 40 (FIG. 2,4).The manual recline collar 62 is pivotal around the slotted ring 38 in arotational range defined by engagement of the stop tabs 88 with opposingcircumferential ends of the pivot limit gaps 86. The manual reclinecollar 62 can be pivoted between a recline-locked position and arecline-unlocked position.

The second end of the manual recline collar 62 has recline recesses 90in one-to-one correspondence with the recline bearings 70 and thecapture slots 64 of the slotted ring 38 of the outer shaft 26. Therecline recesses 90 are uniformly spaced circumferentially around theinterior of the manual recline collar 62 and are separated by radiallyinward facing lock surfaces 92 that engage the recline bearings 70 whenthe manual recline collar 62 is in a first rotational position, termedas the recline-locking position, as shown in FIG. 8. The reclinerecesses 90 have ramped edges leading to the lock surfaces 92 tofacilitate smooth transition of the recline bearings.

FIG. 8 shows the control ring 56, recline bearings 70, and manualrecline collar 62 without the outer shaft 26. In the assembled rotarylock mechanism 20, the slotted ring 38 of the outer shaft is radiallypositioned between the control ring 56 and the manual recline collar 62,with the capture slots 64 retaining the recline bearings 70. In therecline-locked position of the manual recline collar 62 shown in FIG. 8,the lock surfaces 92 align with the capture slots 64 of the slotted ring38 and press the recline bearings 70 inward, which are thereby offsetradially inward and engage the recline control grooves 76 of the controlring 56. As long as the recline bearings 70 are maintained as offsetinward by the manual recline collar 62, and at the second ends of thecapture slots 64 by the linear bias springs 72, each recline bearing 70engages a respective recline control groove 76 at the first indexposition 81, second index position 82, or third index position 83.

In a second rotational position of the manual recline collar 62, termedas the recline-unlocked position, the recline recesses 90 align with thecapture slots 64 of the slotted ring 38, thus permitting the reclinebearings 70 to offset radially outward into the recline recesses 90 andescape the recline control grooves 76 of the control ring 56. Thisdisengages the recline bearings 70 from the control ring 56 and permitsthe control ring 56 to rotate relative to the outer shaft 26 within therecline range. As the control ring 56 rotates, the index positions ofcontrol grooves of the control ring 56 align selectively with the relinebearings. For example, starting in the upright position of the backrest34, the first index positions 81 of the control grooves 76 align withthe recline bearings 70. Upon rotation of the control ring 56 by a firstreclining increment 91 (FIG. 6), the second index positions 82 alignwith the recline bearings 70 and the backrest 34 is moved from theupright position to the partial reclined position. Upon rotation of thecontrol ring 56 by a second reclining increment 92 (FIG. 8), the thirdindex positions 83 align with the recline bearings 70 and the backrest34 is moved from the partial reclined position to the maximum reclinedposition. These rotations of the control ring 56 referenced as the firstincrement 91 and second increment 92 in FIG. 6 are correlatedrespectively with repositioning of the recline bearings 70 relative tothe control ring 56 with a first reclining step 93 from the first indexposition 81 and a second reclining step 94 to the third index position83. The backrest 34 can be returned from the maximum reclined positionto the partial reclined position or upright position by reversing themovements of the control ring 56 as long as the manual recline collar 62is maintained in the recline-unlocked position.

The manual recline collar 62 is biased toward the recline-lockedposition for stable use. This maintains the backrest 34 in any selectedrecline or upright position. The adjustment of the backrest 34 may beperceived by a passenger as direct from the upright position to themaximum reclined position without stopping at the partial reclinedposition. Upon return of the manual recline collar 62 to the reclinelocked position, the control ring 56 settles into a position in whichone of the index positions of the control grooves align with therespective recline control bearings and the backrest 34 locks into itscorresponding recline position.

While various other ways of pivoting the manual recline collar 62 arewithin the scope of these descriptions, a shifting bracket 106 extendsradially outward from the illustrated manual recline collar 62 (FIG. 7)for use in pivoting the collar between the recline-locked position andthe recline-unlocked position. FIG. 8 shows a particular example of arecline control device 108 engaging the manual recline collar 62 by wayof the shifting bracket 106. The recline control device includes aBowden cable 110 having a first end engaged with the manual reclinecollar 62 and the outer shaft 26 (FIG. 2), and a second end engaged witha manually actuated levered device 112 (FIG. 6). At the first end of theBowden cable, a flexible inner cable 114 engages the shifting bracket106 and an outer cable housing 116 engages a fixed bracket 118 connectedto the base plate 40 of the outer shaft 26. At the second end of theBowden cable 110, the levered device 112 is used to transmit mechanicalforce to the first end by manual actuation of a button 120 that rocks alever and moves of the inner cable 114 relative to the cable housing116. As the inner cable 114 is pulled relative to the cable housing atthe second end of the Bowden cable, the manual recline collar 62 isrotated relative to the outer shaft 26 from the recline-locked positionto the recline-unlocked position. The manual recline collar 62 is biasedtoward the recline-locked position by a spring 122 surrounding the innercable 114 between the shifting bracket 106 and fixed bracket 118,maintaining the backrest 34 in any selected recline or upright position.

As described above, with the recline bearings 70 maintained at thesecond ends of the capture slots 64, the manually controlled rotationalposition of the manual recline collar 62 determines whether the controlring 56 can rotate relative to the outer shaft 26. However, the linearbias springs 72 that press the recline bearings 70 toward thelongitudinal end of the outer shaft can be overcome. This relates to amanual override feature that permits a recline setting to be overcome,by force, to return the backrest 34 to an upright position without useof the recline control device 108.

Each recline control groove 76 (FIG. 6) has groove sectionsinterconnecting the multiple index positions, each of which defines aterminus of its corresponding control groove directed toward the secondlongitudinal end 55 of the control ring 56. A linear first groovesection 101 extends longitudinally and terminates at the first indexposition 81. A helical second groove section 102 extends longitudinallyand circumferentially and terminates at the second index position 82. Ahelical third groove section 103, in similarity with the helical secondgroove section 102, extends longitudinally and circumferentially andterminates at the third index position 83. The end of each groovesection directed toward the first end 54 of the control ring 56 isjoined to each adjacent groove section, permitting the associatedrecline bearing 70 to travel within the control groove among the indexpositions, with the longitudinal component of any such travel affectingthe length of the linear bias spring 72 that persistently presses therecline bearing 70 toward the index positions. Relative to the slottedring 38 of the outer shaft 26, each recline bearing 70 can travellinearly, longitudinally in particular, due to the capture of eachrecline bearing 70 within a respective capture slot 64 (FIG. 5). Thetravel of the recline bearings 70 within the helical second and thirdgroove sections correspond to pivoting movement of the control ring 56relative to the outer shaft 26.

The manual override feature, by which a recline setting can be overcomeby force imparted, for example, on the backrest 34 in FIG. 1 to returnthe backrest 34 to an upright position, is facilitated by the helicalgroove sections and spring-biased recline bearings 70. Starting in themaximum recline position of the backrest 34, the third index positions83 (FIG. 6) of the control grooves 76 align with the recline bearings70. Sufficient torque applied to the control ring 56 by way ofsufficient force on the backrest 34 toward the partial reclined positioncauses the linear springs 72 to be overcome as the control ring 56 isrotated by a first uprighting increment 95 to align the second indexpositions 82 with the recline bearings 70. With continued or additionalforce on the backrest 34 toward the upright position, the control ring56 can be further rotated by a second uprighting increment 96 to alignthe first index positions 81 with the recline bearings 70.

These manual override adjustments occur with the manual recline collar62 in the recline-locked position of FIG. 8. The lock surfaces of themanual recline collar 62 align with the capture slots 64 of the slottedring 38 and press the recline bearings 70 inward, which are therebyoffset radially inward and engage the recline control grooves 76 of thecontrol ring 56. The rotations of the control ring 56 referenced as thefirst uprighting increment 95 and second uprighting increment 96 in FIG.6 are correlated respectively with repositioning of the recline bearings70 relative to the control ring 56 by a movement 97 along the helicalthird groove section 103 and a movement 98 along the helical secondgroove section 102. The uprighting increments 95 and 96, which arecorrelated with uprighting of the backrest 34, are in a rotationaldirection opposite that of the reclining increments 91 and 92, which arecorrelated with reclining of the backrest 34.

To prompt the uprighting increments, force applied to the backrest 34 isconverted to torque about the pivot axis 22, and the torque is convertedto linear force upon the recline bearings 70 by the helical groovesections 103 and 102 to overcome the linear bias springs 72. However,the linear first groove 101 section extends longitudinally, and thusrotation beyond the second uprighting increment 96 in FIG. 6 isprevented as the backrest 34 reaches the upright position. Furthermore,the helical second groove section 102 and helical third groove section103 extend circumferentially in a common direction from the second indexposition 82 and third index position 83, respectively, to facilitateonly one-way conversion of torque to force on the recline bearings 70and linear bias springs 72. The override feature thus operates to permituprighting rotation of the control ring 56 relative to the outer shaft26 in response to uprighting forces on the backrest 34, while preventingrotation in reverse and preventing the backrest 34 from being furtherreclined from any given recline setting without use of the reclinecontrol device 108. Movement beyond the recline range is furtherprevented by the first-end tabs 58 of the control ring 56 in therespective slots 60 in the base plate 40 of the outer shaft.

The recline control grooves 76 have arcuate walls accommodating theradii of the recline bearings 70 and facilitating the first recliningstep 93 and a second reclining step 94 when the manual recline collar 62is in the recline-unlocked position, and facilitating the overrideuprighting movements 97 and 98 along the helical groove sections whenthe manual recline collar 62 is in the recline-locked position.

The manual override feature, by which a recline setting can be overcomeby force, permits a backrest to be returned to upright without use ofthe recline control device 108, whether the force be imparted by apassing airline attendant prepping an occupied or unoccupied seatassembly for use, or whether the force be imparted by an aft-seatedpassenger impacting the backrest. By permitting a reclined backrest toreturn to upright under force, the override feature also serves as abreakover feature to prevent or reduce injury to an aft-seated passengerby energy dissipation as the backrest returns toward upright.

Throughout the above described manual reclining and manual overridefunctions of the multi-functional rotary lock mechanism 20, the controlring 56 is considered as non-rotationally engaged with the inner shaft30. Thus, as the control ring 56 is permitted to partially rotate aboutthe pivot axis 22 relative to the outer shaft 26, the inner shaft 30rotates with the control ring 56. In the example of FIG. 1, thiscorresponds to the backrest 34, to which the inner shaft 30 isconnected, pivoting relative to the frame member 32 to which the outershaft 26 is connected. The rotary lock mechanism 20 further has anautomatic breakover release feature, which permits the backrest 34 topivot forward under emergency circumstances despite the position of thecontrol ring 56.

In particular, the position of a second collar, referenced as theautomatic release collar 130, determines whether the control ring 56 canrotate relative to the inner shaft 30. A ring of lock notches 78 (FIG.6) is defined between the ring of recline control grooves 76 and thesecond end 55 of the control ring 56. The lock notches 78 are uniformlyspaced circumferentially around the exterior of the control ring 56 inone-to-one correspondence with second bearings, referenced as automaticrelease bearings 80. The release bearings 80 are shown as ball bearingsin the illustrated example.

The inner shaft 30 has a longitudinally extending cylinder 132 with afirst end 134 for attachment to a pivotal structure such as the backrest34 of FIG. 1 and a second end 136 near which a ring of capture holes 138is defined. Mounting plates 140, which extend radially outward from thefirst end 134, have mounting holes by which the inner shaft 30 can benon-rotationally attached to a pivoting structure, such as the pivotingbackrest 34 of FIG. 1, using fasteners, such as bolts as illustrated.

The capture holes 138 are uniformly spaced circumferentially inone-to-one correspondence with the automatic release bearings 80 andlock notches 78, which are radially beneath the automatic release collar130. Each capture hole is defined through the second end 136 of thecylinder 132, permitting a respective release bearing 80 within eachcapture hole 138 to offset radially inward from the hole toward thecontrol ring 56 or offset radially outward from the hole toward themanual recline collar 62. The release bearings 80 are dimensioned toremain partially within the capture holes 138 in either offset position.The rotational position of the automatic release collar 130 determineswhether the control ring 56 can rotate relative to the inner shaft 30according to whether the release bearings 80 are pressed inward toengage the control ring 56 or permitted to offset outward to disengagefrom the control ring 56.

In the assembled rotary lock mechanism 20, (FIG. 3), the automaticrelease collar 130 is positioned longitudinally adjacent the manualrecline collar 62. The second end 55 of the control ring 56 (FIG. 6) isreceived within the second end 136 of the cylinder 132 of the innershaft 30, which abuts the longitudinal end of the slotted ring 38 of theouter shaft 26 as shown in FIG. 5. The release collar 130 is pivotallymounted on the second end of the cylinder surrounding the capture holes138. The release collar 130 has release recesses 142 in one-to-onecorrespondence with the release bearings 80 and the capture holes 138.The release recesses 142 are uniformly spaced circumferentially aroundthe interior of the release collar 130 and are separated by radiallyinward facing lock surfaces 144 that engage the release bearings 80 whenthe release collar 130 is in the locked position as shown in FIG. 11.The release recesses 142 have ramped walls leading to the lock surfaces144 to facilitate transition of the release bearing 80.

In the locked position of the automatic release collar 130 (FIG. 11),the lock surfaces align with the capture holes 138 of the inner shaft 30and press the release bearings 80 inward, which are thereby offsetradially inward and engage the lock notches 78 of the control ring 56(FIG. 6). As long as the release bearings 80 engage the control ring 56,the inner shaft 30 and control ring 56 are non-rotationally engaged.

The automatic release collar 130 can be pivoted from the locked position(FIG. 11) to a release position (FIG. 12). In the release position ofthe release collar 130, the release recesses 142 align with the captureholes 138 of the inner shaft 30, thus permitting the release bearings 80to offset radially outward into the release recesses 142 and escape thelock notches 78 of the control ring 56. This disengages the releasebearings 80 from the control ring 56 and permits the control ring 56 torotate relative to the inner shaft 30 within a limited release rotationrange.

Second-end tabs 59 (FIGS. 3-5) that extend longitudinally from thesecond end 55 of the control ring 56 limit the release rotation range byengaging the inner shaft 30. Each second-end tab 59 is received by arespective arcuate track 146 (FIG. 10) defined in an annular lip 148within the second end 136 of the inner shaft 30. The arcuate lengths ofthe tracks 146 relative to the dimensions of the second-end tabs 59permit the control ring 56 to pivot relative to the inner shaft 30within the release rotation range corresponding to a pivotal rangeavailable to the backrest 34 upon release of the control ring 56 fromthe inner shaft 30 by the automatic release collar 130. These automaticrelease features permit the backrest to pivot forward under suchemergency circumstances such as rapid aircraft decelerations andimpacts, preventing or reducing the likelihood of a passenger striking abackrest 34 from behind with enough force to cause serious injury. In atleast one embodiment, the release rotation range predetermined byengagement of the second-end tabs 59 with the tracks 146 permits thebackrest 34 to move forward beyond the upright position but stops thebackrest from reaching a seat pan of a seat assembly under breakoverconditions.

While various other ways of pivoting the automatic release collar 130are within the scope of these descriptions, a shifting tab 150 (FIG. 9)extends radially outward from the automatic release collar 130 for usein pivoting the collar between the locked position (FIG. 11) and therelease position (FIG. 12). FIGS. 2 and 11-12 shows a particular exampleof an automatic release device 152 engaging the release collar 130 byway of the shifting tab 150. The automatic release device 152 includes afirst link 154 and a second link 156 that cooperatively position theautomatic release collar 130.

A parallel pair of hinge plates 158 extends radially from the exteriorof the cylinder of the inner shaft 30. The first link 154 is pivotallymounted at its first end to the inner shaft 30 between the hinge plates158. A second end of first link 154 is pivotally attached to a first endof the second link 156. A trigger arm 160 extends from the first end ofthe first link 154. A second end of the second link 156 is pivotallyattached to the shifting tab 150 of the automatic release collar 130.When the automatic release collar 130 is in the locked position, thetrigger arm 160 extends radially from the first link 154. Movement ofthe trigger arm 160 causes the first link 154 to draw the first end ofthe second link 156 radially outward, causing the second link the pullthe shifting tab 150 and automatic release collar 130 to the releaseposition. In the illustrated embodiment, an inertial mass 162 is mountedon the trigger arm 160 such that inertial forces can prompt the releaseof the automatic release collar 130. In particular, the automaticrelease device 152 causes pivoting of the automatic release collar 130from the locked position to the release position upon forward movementof the intertial mass 162 relative to the inner shaft 30 under suchemergency circumstances such as rapid aircraft decelerations andimpacts. This may precede an aft-seated passenger imparting forces uponthe backrest. Thus, by this feature, the backrest may be released topivot forward as or before a passenger strikes the backrest from behind.

The rotary lock mechanism 20 includes a torsion spring 166 thatpersistently biases the inner shaft 30 relative to the outer shaft 26 toa relative pivotal position corresponding to the upright position of thebackrest 34 in the example of FIG. 1. A first end of the torsion springhas a radially inward extending segment 168 (FIG. 3) thatnon-rotationally engages the outer shaft 26, particularly by use of acable tie 170 as illustrated in FIG. 3 or other fastener. A second endof the torsion spring 166 has a radially outward extending segment 172that engages the inner shaft 30 via a stop tab 174 (FIG. 2) that extendslongitudinally from the first end 134 of the inner shaft 30. The torsionspring 166 has a helical coil positioned concentrically within thecentral shaft 36. The torsion spring 166 returns or assists the backrest34 to its upright position when the manual recline collar 62 permits.

An interior bushing 176 (FIG. 4) has a cylindrical body positionedconcentrically between the inner cylindrical wall of the central shaft36 and the helical coil of the torsion spring 166 to facilitatedeformations of the coil and protect the central shaft 36 as the rotarylock mechanism 20 operates. The interior bushing 176 has an annular lip178 that extends from the cylindrical body and pivotally engages theinner shaft 30 helping maintain alignment of the inner shaft 30 andouter shaft 26.

An assembly bushing 180 maintains the inner shaft 30 in alignment andassembly with the outer shaft 26. An annular lip 182 within the firstend 134 of the inner shaft 30 receives and engages the assembly bushing180. The assembly bushing 180 receives the longitudinal end 50 of thecentral shaft 36 and helps to maintain alignment of the inner shaft 30and outer shaft 26 while permitting the inner shaft 30 to pivot as therotary lock mechanism 20 operates. The circumferential locking groove 48of the central shaft 36 extends longitudinally beyond the assemblybushing 180 with sufficient tolerance to permit the lock ring 52 to snapinto the locking groove 48 in the assembled mechanism (FIG. 2), trappingthe assembly bushing 180 and other components therewith on the centralshaft 36 while permitting the above-described pivotal movements.

The multi-functional rotary lock mechanism 20 furthermore serves as apivotal mount for a third seat assembly component, such as a tablebehind the backrest 34 in the example of FIG. 1. A support arm,referenced as a table support arm 184, is shown in FIG. 13 in a firstpivotal position corresponding to deployment of a table behind thebackrest 34 in the example of FIG. 1. FIG. 14 shows the table supportarm in a second pivotal position corresponding to stowing of a table. Asshown in FIG. 4 the arm 184 includes a linear portion 186 that extendsradially to support a table. A mounting hook 188 is connected to thelinear portion to engage the exterior of the cylinder of the inner shaft30. An engagement tooth 190 extends radially inward from a terminal endof the mounting hook.

A circumferentially extending first engagement slot 37 (FIG. 13) isdefined through the central shaft 36, and a circumferentially extendingsecond engagement slot 31 (FIG. 5) is defined through the cylinder ofthe inner shaft 30. The first engagement slot 37 is a feature of theouter shaft 26, and so, in the example of FIG. 1, the first engagementslot 37 is stationary with the frame member 32 of the seat assembly. Aforward end of the first engagement slot 37 limits the maximumdeployment angle of the table support arm. The second engagement slot 31pivots with the inner shaft 30 as the backrest 34 is reclined andreturned toward upright. By engaging the tooth 190 as the table supportarm is returned toward upright, a rearward end of the second engagementslot 31 limits the pivotal range available to the table support arm tocorrespond to the current recline angle of the backrest 34. This featureprevents the table support arm from passing the backrest 34 in theirreturn toward upright.

While the foregoing description provides embodiments of the invention byway of example only, it is envisioned that other embodiments may performsimilar functions and/or achieve similar results. Any and all suchequivalent embodiments and examples are within the scope of the presentinvention and are intended to be covered by the appended claims.

What is claimed is:
 1. A lock mechanism for controlling a rotatingcomponent, comprising: an outer shaft attachable to a stationarycomponent, the outer shaft having a slotted ring defining capture slotsand an interior annular space; a control ring having a first enddisposed in the annular space; an inner shaft attachable to a rotatingcomponent, the rotating component configured to rotate relative to thestationary component, and the inner shaft engaged with a second end ofthe control ring; a first collar rotatably disposed around the slottedring, the first collar having a plurality of release recesses; and aplurality of first bearings respectively retained within the captureslots beneath the first collar, wherein: in a first rotational positionof the first collar, the plurality of release recesses align with thecapture slots to rotationally disengage the rotating and stationarycomponents; and in a second rotational position of the first collar, theplurality of release recesses misalign with the capture slots torotationally engage the rotating and stationary components.
 2. The lockmechanism of claim 1, wherein the stationary component is a stationaryseat assembly component and the rotating component is a pivoting seatassembly component.
 3. The lock mechanism of claim 1, wherein in thefirst rotational position of the first collar, the first bearings arepartially offset from the capture slots toward the control ring; and, inthe second rotational position of the first collar, the first bearingscan partially offset from the capture slots toward the first collar. 4.The lock mechanism of claim 1, wherein the outer shaft comprises acentral shaft, and the interior annular space is defined between thecentral shaft and the slotted ring.
 5. The lock mechanism of claim 4,wherein the central shaft has a longitudinal end that extends beyond theslotted ring and is received by the inner shaft.
 6. The lock mechanismof claim 1, further comprising a second collar rotatably disposed aroundan end of the inner shaft, wherein: in a first rotational position ofthe second collar, the inner shaft is non-rotationally engaged with thesecond end of the control ring; and in a second rotational position ofthe second collar, the inner shaft is rotationally disengaged from thesecond end of the control ring.
 7. The lock mechanism of claim 6,further comprising a plurality of second bearings respectively retainedwithin capture holes in the end of the inner shaft beneath the secondcollar, wherein, in the first rotational position of the second collar,the second bearings are partially offset from the capture holes towardthe control ring; and, in the second rotational position of the secondcollar, the second bearings can partially offset from the capture holestoward the second collar.
 8. The lock mechanism of claim 6, furthercomprising a manual control device engaging the first collar andoperable to move the first collar between a first rotational positionand a second rotational position thereof.
 9. The lock mechanism of claim6, further comprising an automatic release device engaging the secondcollar and operable to move the second collar between a first rotationalposition and a second rotational position thereof.
 10. The lockmechanism of claim 9, wherein the automatic release device comprises aninertial mass on a trigger arm movable by inertial forces to move thesecond collar to the second rotational position.
 11. The lock mechanismof claim 1, further comprising an arm pivotally-mounted on the innershaft.
 12. The lock mechanism of claim 1, wherein the control ring hashelical grooves in which the first bearings are movable against theforces of springs, when the first collar is in the first rotationalposition, by a force to overcome the springs thereby permitting therotating component to rotate relative to the stationary component.
 13. Apassenger seat assembly, comprising: a stationary frame member; arotating component configured to rotate relative to the stationary framemember; and a lock mechanism for controlling rotation of the rotatingcomponent relative to the stationary frame member, the lock mechanismcomprising: an outer shaft attached to the stationary frame member, theouter shaft having a slotted ring defining capture slots and an interiorannular space; a control ring having a first end disposed in the annularspace; an inner shaft attached to the rotating component, the innershaft engaged with a second end of the control ring; a first collarrotatably disposed around the slotted ring, the first collar having aplurality of release recesses; and a plurality of first bearingsrespectively retained within the capture slots beneath the first collar,wherein: in a first rotational position of the first collar, theplurality of release recesses align with the capture slots torotationally disengage the stationary frame member and rotatingcomponent; and in a second rotational position of the first collar, theplurality of release recesses misalign with the capture slots torotationally engage the stationary frame member and the rotatingcomponent.
 14. The passenger seat assembly of claim 13, wherein therotating component is a backrest, a leg rest, or an armrest.
 15. Thepassenger seat assembly of claim 13, wherein in the first rotationalposition of the first collar, the first bearings are partially offsetfrom the capture slots toward the control ring; and, in the secondrotational position of the first collar, the first bearings canpartially offset from the capture slots toward the first collar.
 16. Thepassenger seat assembly of claim 13, wherein the outer shaft comprises acentral shaft, and the interior annular space is defined between thecentral shaft and the slotted ring.
 17. The passenger seat assembly ofclaim 16, wherein the central shaft has a longitudinal end that extendsbeyond the slotted ring and is received by the inner shaft.
 18. Thepassenger seat assembly of claim 13, further comprising a second collarrotatably disposed around an end of the inner shaft, wherein: in a firstrotational position of the second collar, the inner shaft isnon-rotationally engaged with the second end of the control ring; and ina second rotational position of the second collar, the inner shaft isrotationally disengaged from the second end of the control ring.
 19. Thepassenger seat assembly of claim 13, further comprising a plurality ofsecond bearings respectively retained within capture holes in the end ofthe inner shaft beneath the second collar, wherein, in the firstrotational position of the second collar, the second bearings arepartially offset from the capture holes toward the control ring; and, inthe second rotational position of the second collar, the second bearingscan partially offset from the capture holes toward the second collar.20. The passenger seat assembly of claim 13, further comprising a manualcontrol device engaging the first collar and operable to move the firstcollar between first rotational position and second rotational positionthereof.